ka24de rough idle and won't pull

[emerica9004]

My '91 240 will start up fine and idle fine for a few minutes but then after warming up it will idle between 400 and 1000 rpm. then when I drive it won't accelerate very good and it almost stops pulling in 4th and 5th gear. If I unhook the larger vaccuum hose on the air intake on the left it idles better but still wont pull very good. This is my first time driving it since I have gotten it running so I don't know how it ran before I bought it or what could be wrong. Thanks in advance.

[mb_s13]

Check the timing.

[emerica9004]

i will try.

[leper421]

My '91 240 will start up fine and idle fine for a few minutes but then after warming up it will idle between 400 and 1000 rpm. then when I drive it won't accelerate very good and it almost stops pulling in 4th and 5th gear. If I unhook the larger vaccuum hose on the air intake on the left it idles better but still wont pull very good. This is my first time driving it since I have gotten it running so I don't know how it ran before I bought it or what could be wrong. Thanks in advance.

Does it drive OK in the first few minutes before it's warmed up and before the idle changes? When you disconnect the hose, are you plugging both ends?

[emerica9004]

Does it drive OK in the first few minutes before it's warmed up and before the idle changes? When you disconnect the hose, are you plugging both ends?

I haven't driven it before it warms up. I have only taken it out twice. I unplug the hose at the air cleaner. It has vaccuum but when I plug it it shus off, like it should I would assume.

[leper421]

I haven't driven it before it warms up. I have only taken it out twice. I unplug the hose at the air cleaner. It has vaccuum but when I plug it it shus off, like it should I would assume.

What line are you disconnecting? The hose that connects to the rear of the air-box is the AIV line. Any vacuum line that you disconnect has to be plugged at both ends, otherwise you are NOT diagnosing anything, you are only introducing a vacuum leak into the system...

[emerica9004]

This one.

[leper421]

There are two hoses that come off the intake tubing in the location you pointed to. One hose is bigger than the other. The larger hose goes to the idle control valves, while the smaller hose is for the crankcase ventilation (I'm not 100% sure the previous sentence it true). Disconnecting either hose will allow air into the intake manifold that is not measured by the mass air flow sensor (in other words: a vacuum leak).

I asked about driving before it warms up because there is a temperature controlled valve that lets more air into the manifold when the engine is cold, to increase the idle speed in order to warm up the engine faster.

[emerica9004]

The one that I disconected was the ICV. Yeah I haven''t had the chance to take it out cold yet. I bought it not running and just got it there and I am now stumped. Thank you for the help.

[nismoboy92]

might be a bad maf sensor.

[emerica9004]

Thats what I though. I took it off and it had some crud on the metal wires so I will try to clean it.

[leper421]

Thats what I though. I took it off and it had some crud on the metal wires so I will try to clean it.

How do you plan to clean it? A lot of different chemical cleaners will leave behind residues that mess with the values the MAFS returns. Do not under any circumstances use physical force to remove the "crud".

!!! --------- BE VERY CAREFUL WITH THE MAFS --------- !!!

If I still had my 240, I'd refresh my memory about what the the MAFS looks like. I know the 240 MAFS only samples a small portion of the air flow in a small chamber adjacent to the main airway.

The MAFS works by measuring how much heat is dissipated over the wire due to air cooling. Temperature is directly related to electrical resistance, which will change the amount of current passing through the wire and the voltage drop across the wire.

I doubt this is a problem with your MAFS, but I could be wrong...
Modified by leper421 at 9:01 PM 7/11/2008

[emerica9004]

How do you plan to clean it? A lot of different chemical cleaners will leave behind residues that mess with the values the MAFS returns. Do not under any circumstances use physical force to remove the "crud".

!!! --------- BE VERY CAREFUL WITH THE MAFS --------- !!!

If I still had my 240, I'd refresh my memory about what the the MAFS looks like. I know the 240 MAFS only samples a small portion of the air flow in a small chamber adjacent to the main airway.

The MAFS works by measuring how much heat is dissipated over the wire due to air cooling. Temperature is directly related to electrical resistance, which will change the amount of current passing through the wire and the voltage drop across the wire.

I doubt this is a problem with your MAFS, but I could be wrong...

Modified by leper421 at 9:01 PM 7/11/2008

I was THinking about using alcohol to clean it up. I know to be careful when cleaning it.

[yummyjapan]

hey man u seem to know your stuff about these cars i would like to talk to you about my car idling at 1800 rpms i cleaned the throttle body with carb and choke cleaner and i disconnected the tps while the car was running and nothing happened so i am not really sure what to do and my car doesn't pull at all under full throttle there are some emissions things disconnected i don't know what to do or if i should even wast my time

[emerica9004]

I would first go through all of the emissions lines and check to see where they go to. And if all of the connectors and hoses are there hook them back up. I still haven't gotten mine to run right. I spent the past few days replacing the front main seal and looking for the other half of the upper timing chain guide. If anyone has any clue as to where to look for the other half in the engine let me know. I hear it rattling around in there but I can''t find it. I think it dropped down towards the oil pan.

[leper421]

hey man u seem to know your stuff about these cars i would like to talk to you about my car idling at 1800 rpms i cleaned the throttle body with carb and choke cleaner and i disconnected the tps while the car was running and nothing happened so i am not really sure what to do and my car doesn't pull at all under full throttle there are some emissions things disconnected i don't know what to do or if i should even wast my time

What emission devices are disconnected? If you don't know the names of the various components, please provide pictures. If a vacuum hose/tube is disconnected but not plugged, it will cause problems... provide more info/pics.

[leper421]

I would first go through all of the emissions lines and check to see where they go to. And if all of the connectors and hoses are there hook them back up. I still haven't gotten mine to run right. I spent the past few days replacing the front main seal and looking for the other half of the upper timing chain guide. If anyone has any clue as to where to look for the other half in the engine let me know. I hear it rattling around in there but I can''t find it. I think it dropped down towards the oil pan.

He/she was asking me (notice the winking smile...)

There are two upper timing chain guides, one is on top of the upper chain. You can see it (if its still there) by removing the valve cover. If you see a broken piece of metal over the top of the chain that is bolted to the head by two bolts in between the cams, then the top guide broke off (very common). The other guide is on the right side of the chain (when viewed from the front of the engine). You can only see this if you remove the upper timing cover.

When you replaced the front main seal did you remove the lower timing cover? Unless someone previously removed the lower timing cover and didn't replace the one stupid bolt that attaches the oil pickup to the block, you would have had to remove the oil pan to get the lower cover off. If so, you would have seen the broken upper guide. The upper guides are not needed, and are not supplied in replacement timing chain kits. Remove them if they are still there.

If your upper guide(s) didn't break off then what you are hearing is probably the lower chain slapping against the lower cover. Eventually the chain will wear into the lower cover, and open a hole into a coolant passage, and dump all your coolant into your oil pan. A timing chain kit is ~$200. The tensioners are the main important items. Expect to spend 2-3 full days to replace the chain and tensioners, and that is if you know what you are doing.

I apologize if the above description is lacking proper grammar or sentence structure. It's late at night...

[emerica9004]

well I took off the top timing cover and took out the guide on the left side and the one on the top. The top one is broken and I still can't find the other half. Since the car still isn't running right and isn't road legal, I am going to pull off both front covers and the oil pan and replace both timing chains. Then maybe I will find the other half. I was hoping it would find it's way back to the top of the engine but that's a big gamble to take.

[leper421]

well I took off the top timing cover and took out the guide on the left side and the one on the top. The top one is broken and I still can't find the other half. Since the car still isn't running right and isn't road legal, I am going to pull off both front covers and the oil pan and replace both timing chains. Then maybe I will find the other half. I was hoping it would find it's way back to the top of the engine but that's a big gamble to take.

The top guide is most likely in your oil pan.

Removing the oil pan is a huge pain in the ***, and it is one of the main reasons that mechanic's estimates for replacing the timing chain are over $1000, along with the work needed to strip down the entire front of the engine.

In order to to remove the oil pan, you need to lift the engine up so that the oil pan can clear the front cross-member. The nuts on the bolts that hold the mounts to the cross-member will most likely be seized, and you will just wind up rounding off the nuts while trying to loosen them. The nuts that attach the mounts to the mount brackets that bolt to the block may be in the same state. Those nuts also have a very limited access angle. The easiest way to detach the engine (and the most difficult to reattach) is to remove the four bolts on each side that bolt the engine to the mount brackets.

After that, put a jack under the bell housing of the transmission and jack the engine up enough to give you clearance to slide the oil pan out.

[emerica9004]

That sounds like a task. Thanks for the help I guess that will be next weeks project for me then.

[yummyjapan]

i got everything hooked back up as far as emissions r concerned my fuel filter and mas air flow sensor need replaced though so after i do that i think it will run properly i am on hold right now for purchasing that stuff though cause my back tires blew out cause the dumb a$$ kid i bought my car from didn't install a camber kit on the car after lowering it so 2 new tires set me back 170 bucks. next i am getting those parts then a camber kit then a s13 black top but other than these few problems i have been having i like this car more then my 530whp 95 gsx eclipse cause that thing broke constantly and it was always a turbo a transmission or a motor

p.s i love nissan

[leper421]

2 new tires set me back 170 bucks.

$170 for two tires? That's it? PSSHT... I recently spent over $800 on four tires for my Z

Let me know if you have any other questions about the s13. I've repaired or replaced almost everything possible, and want to use my experience to help other s13 owners.

Also, it's not considered good forum manners to hijack someone else's thread

[yummyjapan]

dude my tires were some kumhos thats why they are so cheap plus they are on my stock wheels 195-60-15 and is my thread the i love nissan thing

[emerica9004]

Nice car you got there. Before you buy a new MAF get some of the CRC MAF cleaner from an auto parts store. It's cheaper than a new one and worth the try, plus it can clean other electrical stuff inside the engine bay.

[yummyjapan]

thanx man but it still has a long way to go alright i will try that cleaner thanx for the info man

[emerica9004]

Mine does too but what good is a car that you don't get to do work to? Good luck.

[leper421]

dude my tires were some kumhos thats why they are so cheap plus they are on my stock wheels 195-60-15 and is my thread the i love nissan thing

I was attempting to be sarcastic/funny... It absolutely sucks that a good brand of high performance tires costs over $800 after mounting/balancing and tax (two 225/50-ZR-17, and two 235/50-ZR-17).

Nico's smile icons suck... for future reference, smiles are yellow, winking smiles are dark blue.

Also, as a blatant advertisement, I have a bunch of S13 parts I'm looking to get rid of. See the link in my message tagline.

[yummyjapan]

hey man i replaced my fuel filter my injectors my iacv new cap new rotor new plugs new wires and it got better but not perfect and i put the number one cylinder at tdc on (compression stroke) and put the rotor pointing at the number one cylinder and when i put the car back together it wouldn't run, am i setting the timing wrong or do u think i have bigger issues ohh and the part of the rotor with the metal going to the end is the part that should point to the number 1 cylinder right.

[leper421]

hey man i replaced my fuel filter my injectors my iacv new cap new rotor new plugs new wires and it got better but not perfect and i put the number one cylinder at tdc on (compression stroke) and put the rotor pointing at the number one cylinder and when i put the car back together it wouldn't run, am i setting the timing wrong or do u think i have bigger issues ohh and the part of the rotor with the metal going to the end is the part that should point to the number 1 cylinder right.

You are setting the timing right. You just said it got better, and that its not running, in the same post... Please clarify what the current situation is.

[yummyjapan]

after i replaced all that stuff the car did run better but still idled hi and had no power at 3000 to 4000 rpms and at full throttle. Then i tried to set the timing and it went down hill from there i think i am just gonna replace the motor cause even if i fix all this its still gonna be slow